Controlling means for prime movers



Nov. 19, 1940. FERGUSON 2,221,791

CONTROLLING MEANS FOR PRIME MOVERS Filed April 18, 1938 5 Sheets-Sheet l6y Mmam' azzj 1940- A. D. FERGUSON CONTROLLING MEANS FOR PRIME MOVERSFiled April 18, 1958 5 Sheets-Sheet 1 n Jillllll Nov. 19, 1940. A. D.FERGUSON CONTROLLING MEANS FOR PRIME MOVERS Filed April 18, 1938 5Sheets-Sheet 3 home/for: CZ/examiril y Nov. 19, 1940. D. FERGUSON2,221,791

CONTROLLING MEANS FOR PRIME MOVERS Filed April 18, 1938 5 Sheets-Sheet 4fizuenfir: aiexarzzrfljr gwon.

1940 A. D. FERGUSON CONTROLLING MEANS FOR PRIME MOVERS Filed April 18,1938 5 Sheets-Sheet 5 @QQ k 4 I I I ll M/QMM.

Patented Nov. 19, 1940 UNITED STATES PATENT OFFICE 2,221,791 CONTROLLINGMEANS FOR PRIME MOVERS Application April 18, 1938, Serial No 202,680

2'7 Claims.

My invention relates to controlling means for prime movers, and moreparticularly to controlling means for the steam engines. It has otheraspects which will appear in the course of the following specificationand the appended claims, including the one of steam-driven compressors.

It is desirable, in connection with pressure fluid driven engines, toeffect the regulation thereof in accordance with the load, to providefor a lessthrottled supply of operating fluid when the load increasesand vice verse, to provide for automatic regulation of operating fluidsupply by speed-responsive means, also, to insure against the enginesrunning away in the event of the derangement of any of its controldevices, and to permit immediate stopping thereof'when the engineerconsiders this imperative. It is an object of my invention, in one ofits more specific aspects, to provide an improved control system for anengine which shall by improved means accomplish these several desirableends. It is, more generally, an object of my invention to provide animproved control apparatus for a prime mover. It is a further object ofmy invention to provide, for a compressor driving engine, an improvedcontrol governed by compressor discharge pressure. It is another objectof the invention to provide an improved speed-responsive governor havingimproved means for slowing down or stopping the engine if the speedbecomes too high. It is yet another object to provide an improved safetystop for an engine associated with the speed-responsive governor thereoffor stopping the engine if the drive for said speed-responsive governoris broken. It is still a further object of the invention to provide animproved control mechanism embodying a combination of speed and loadcontrol of novel form. It is a still further object of the invention toprovide for hydraulic governing of a throttle valve controlling acompressordriving engine under speed and compressor discharge pressurecontrol, and again, to provide an improved means whereby separate orcumulative control is possible. Yet another object of the invention isto provide an improved steam-driven compressor. Other objects andadvantages will hereinafter more fully appear.

In the accompanying drawings, in which, for purposes of illustration, anillustrative embodi ment of the invention is disclosed- Fig. 1 is a sideelevation of a steam-driven compressor embodying an illustrative form ofthe invention.

Fig. 2 is a view mainly in section, with parts shown on differentscales, and more or less in the nature of a diagrammatic view, showingmajor elements of the control system.

Fig. 3 is a view of a portion of the mechanism of Fig. 2, showing partsin a different relative position.

Fig. 4 is a detail sectional view on the planes of the section line 4-4of Fig. 2.

Fig. 5 is a fragmentary. view showing a governor drive.

Fig. 6 is a section on the plane of the line 6-6 6 of Fig. 5, showingdetails of construction.

Fig. 7 is a detail section on the line 'I'l of Fig. 5, showing a controlcam.

Fig. 8 is an elevational view of an automatic pressure responsive devicewhich may be used in my improved control system.

Fig. 9 is another detail sectional view, this one on the plane of theline 9-8 of Fig. 2.

Fig. 10 is a fragmentary sectional view showing a portion of themechanism of Fig. 2 with parts in different relative positions.

Fig. 11 is a diagrammatic view showing portions of the system,particularly the pressure-responsive portions thereof.

Figs. 12 and 13 are, respectively, an elevation and a section on theplane of the line l3--I3 of Fig. 12, disclosing a modified form-ofspeed-responsive governor providing for-a wider range of speed control.

Referring to the drawings, it will be observed that my invention in itsillustrative embodiment is incorporated in a steam-driven compressorsystem which includes a multi-stage steam-driven compressor generallydesignated I and comprising a base frame 2 on which there is mounted alow pressure cylinder 3 discharging through a low pressure dischargeline 4 to an intercooler 5, and from the latter an intake line 6 of ahigh pressure cylinder 1, also mounted on the base frame, receives air,while a discharge line 8 conducts the compressed air from the highpressure cylinder 1 herein to a receiver 9. The compressor is providedwith a steam engine III of any suitable construction, and this suppliesthe power for the compression of air in the low and high pressurecylinders. A main steam line H supplies steam to the usual valve chestof a steam cylinder l2 of the engine and a manually operable throttle I3may be closed to stop the steam engine l0. An automatic governormechanism, including an automatic controlling device generallydesignated I4, is arranged between the manual throttle l3 and a steamdelivery line 15.

As shown most clearly in Fig. 2, the automatic controlling device l4includes a casing I! in which a balanced steam-fiow-regulating valve I8is reciprocable; The casing i1 is supported upon a frame l9, and theregulating valve l8 has a stem 20 which extends through a suitable gland2| into the space between legs 22, 22 of the frame [9. A suitable fluidactuated diaphragm 23 is mounted between the bottom of the frame l9 andan element forming a diaphragm chamber 24. A circular plate 25 restsupon the diaphragm and is connected by a suitable yoke 26 to the lowerend 50 of the valve stem 28. The frame I9 provides an abutment 28against which the head 29 of an adjusting screw 38 rests. This adjustingscrew may be moved to alter the position of an abutment 32 for a spring33 which presses upon the upper surface of the circular plate 25 andnormally tends to depress the latter against the pressure exerted uponthe diaphragm 23 and to effect an increased opening of thesteam-fiow-regulating valve I8.

In addition to the diaphragm 23, means for controlling the position ofthe steam-flow-regulating valve I8 is provided, including means foreffecting closure of the regulating valve in the event of loss of theoperating fluid from beneath the diaphragm 23 and means forpermitting-quick stopping of the steam engine I8, if desired, manually.For these purposes there is pivotally supported a lever 35 at 36 uponthe frame I9. This lever carries a substantial weight 31 at its outerend, a weight sufficient, when permitted to fall, to shove thesteam-fiow-regulating valve I8 into closed position. A curved link 39 isprovided with a releasable latch 48 (see Fig. 9) extending into asuitably-formed notch M in the lower end of the link 39, the other sideof the link 39 also having a notch 42 which cooperates with a stationaryprojection 43 to hold the link in the position of Fig. 2 of thedrawings. A diaphragm 45 bounding a liquid-receiving or diaphragmchamber 46 in communication with the system, of which the space beneaththe diaphragm 23 forms a part normally presses a pin 41 carrying thelatch 40 into the recess M and holds the link 39 in the positionrelative to the stop 43 such that the weight 31 is prevented fromdropping. A chain 49 led to any convenient place where it may be quicklyseized and pulled. is arranged to enable the holding effect of the latchmechanism just described to be overcome and to permit substantialinstantaneous manual closing of the steamflow-regulating valve I8, ifdesired.

It will be noted that a fluid conduit 58 having a suitable stop valve 5Itherein leads to the chamber 46, and a conduit 52 leads downwardly tocommunicate with a conduit 53, one of whose ends opens at 54 through themember forming the diaphragm chamber 24 and whose other end opens at 55into a diaphragm chamber 56 shortly to be described in more detail. Thediaphragm chambers and the conduits contain a liquid such as glycerine,and the liquid system may be replenished with liquid, when the valve 5|is open, through a filler cup 56' located at a high point in the system,as shown in Fig. 2. Filling, of course, takes place when the compressorand steam engine are shut down. It will be noted that the structure sofar described contemplates the automatic regulation of the amount ofsteam supplied to the valve chest of the steam cylinder I2, the positionof the steam-fiow-regulating valve I8 to be controlled automatically bythe position of a diaphragm 23, and the position of that diaphragm to becontrolled by liquid pressure in the conduit 52.

For the purpose of controlling automatically the position of thesteam-fiow-regulating valve I8 and for protecting the steam engine I8against running away in the event of certain possible derangements, Ihave provided mechanism which is generally indicated by the referencecharacter 68. This includes speed-responsive mechanism governed by thespeed of the steam engine and compressor; compressor discharge pressureresponsive mechanism; an automatic stop effective in the event ofover-speeding; and a further automatic stop effective in the event ofbreakage of the drive for the speed-responsive mechanism. A casing 6|having a detachable top 62, provides a lubricant reservoir 63 into whichcertain rotating portions of the mechanism within the chamber areadapted to clip for the purpose of throwing the oil and effecting a veryefficient splash lubrication of such mechanism. It will be noted that ahollow tubular shaft 65 is mounted within the casing in antifrictionbearings 66, 61 supported by the end casing walls. On the outside ofthis hollow shaft there is mounted a sleeve 68 pivotally supporting at69 a speed responsive member, herein a wabble plate III. In the form ofmechanism illustrated in Figs. 2 and 3, the hollow shaft supports asliding collar II which is connected by a link I2 with the wabble plate18 and is connected by a transverse pin I3 extending throughlongitudinal slots I4 in the shaft 65, to a cylindrical slide member I5movable within the bore 16 of the hollow shaft. A rod 11 connects theslide member I5 with'another cylindrical slide member I8 which has fixedthereto a short projecting mounting element I9 carrying a thrust ball atits outer end. A comparatively light spring 82 extends between ashoulder 83 within and on the tubular shaft 65 and the right-hand endsurface of the slide member I8 in Fig. 2, and normally tends to move theslide members I8 and I5 and the collar II to the left in Fig. 2. and tocause the wabble plate I8 to move towards perpendicularity to its axisof rotation. The slide member I5 has fixed thereto a projectingspindle-like element 84 which projects beyond the right-hand end of thetubular shaft 65 in Fig. 2 and having a conical or pointed end which isengaged by the cam surface of a cam 85 mounted on an arm 86 (Figs. 2, 3and 5) which is pivoted at 8! (Fig. 6) on the casing 6| and. this armcarries an idler sprocket 88 engaging with a roller drive chain 89driven from the crank shaft 90 of the compressor by a sprocket 9I fixedto the crank shaft and connected by the chain to a sprocket 92 fixed tothe tubular shaft 65. It will be evident that in the event that thisdrive chain 89 should break the support provided for the idler sprocket88 would be lost, and accordingly the arm 86 would swing downwardly andthe cam 85 would thrust the spindle 84 and collar II to the left in Fig.2 of the drawings. This motion will, as will later appear, operate toslow down, or, if carrier far enough, to stop the steam engine II). Aspring 93, more powerful than the spring 82, engages at its right-handend in Fig. 2 the collar II, while its left-hand end is engaged by anadjustable stop member 94, which is mounted on and movable along thetubular shaft 65. This adjustable stop member plays two importantfunctions in the operation of this apparatus. It enables adjustment ofthe compression of the spring 93 and so a variation in theresponsiveness to speed variations of the wabble plate I0. It alsoprovides a very eincient and inexpensive safety stop mechanism. It willbe noted that the member 94 is in the form of an annulus 95 surroundingthe tubular shaft 65 and having diametrically opposite bosses thereon(see Fig. 4). these bosses 96 is comparatively short and provides amounting for a transverse pin 91. The other of these bosses 98 is longerand provides a fork 99 in which a transverse pin I80 is mounted, thispin pivotally supporting a swingable One of speed-responsive member II.The swingable member IOI- likewise carries a transverse pin I02, hereinparallel to the pins 31 and I00, and the opposite ends of this pin areconnected by side springs I03 with the opposite ends of the transversepin 91. These transverse pins are so related to each other and to thepivot pin I00 that the springs I03 normally hold the member I00 in theposition shown in Fig. 2. A guideway I05 in the member 94 is providedfor a toothed latch element I08 which is adapted to engage with a rackI01 carried in a longitudinal slot I00 in the periphery of the tubularshaft 30. The teeth upon the latch I08 and rack I01 are beveled teeth,so that the member 94 may be slid freely to the right in Fig. 2, but notto the left unless the latch I03 is released. The latch is cut away toprovide a shoulder I09 adjacent its lower end, and a striking element orhammer portion I I0 is formed upon the end of the swingable member I 0|at its end nearer the pivot pin I 00. A stop shoulder III engageablewith the side surface of the member 94 is provided to limit the movementof the member IOI about the pivot pin I00. A chamber H2 is provided inthe free end of the swingable member IN to receive mercury, shot orslugs, or other suitable material in the desired quantity to provide forresponse to the desired maximum speed. This automatic stop mechanism asso far described may have its mode of operation briefly summarized atthis point.

It will be appreciated that as the tubular shaft 65 is driven throughthe chain and sprocket connections 89, 9| and 92 the swingable memberIOI which is pivoted on the pin I00 at a point considerably offset fromits center of mass, will be subjected to centrifugal force tending toswing the free end of the member IOI outwardly. This tendency will beresisted by the springs I03 until the line of action of these springs,due to the movement of the pin I02 about the axis of the pin I 00, fallsto the left of the plane including the axes of the pivot pin I00 and thetransverse pin 91. Thereafter, the action of the springs I03 will be inthe same direction with the action of centrifugal force upon the memberIN, and the latter will snap sharply around to the position shown inFig. 3, will cause the hammer portion I I0 to strike against thelatch-shoulder I09 sharply to withdraw the teeth of the latch I00 fromthe teeth of the rack I01, to release the stop member 94 from thetubular shaft 65 and will thus allow the spring 93 to force the stopmember 90 over to the left as viewed in Fig. 3, against the adjacent endof the sleeve 33, thereby reducing the force exerted by the spring 93and allowing the wabble plate 10 to swing outwardly at a much lowerspeed, thereby slowing down the steam englue in through the mechanismwhich will now be described.

It will be noted that the diaphragm chamber 56 shown in Fig. 2, isbounded at its side next to the casing 6| by a diaphragm I20 and that inback to back relation with the diaphragm I20 is another diaphragm I2Ispaced at its periphery from the diaphragm I20 by a comparatively narrowspacer element I22. The diaphragm I2I carries a central re-inforcementand thrusttransmitting mechanism generally designated I23. The thrustball contacts one side of this thrust transmitting and re-enforcementmechanism. The other side provides a spacer between the diaphragms I20and I2I when these are in their most proximate positions. Having in mindthe fact that the fluid system including the chamber 53, the conduits32, 33, the diaphragm chambers l8 and 24 and the sealed portion of theconduit 30 is full of liquid as explained above, it will be appreciatedthat any movement toward the left in Fig. 2 by the diaphragm I20 willexercise a closing influence upon the steam-flow regulating valve I9.Movement of the diaphragm I20 to the left may be effected with theconstruction disclosed either by the exertion of mechanical thruststhereon through the reinforcement and thrust transmitting mechanism I23under the action of the thrust ball 30 or by pneumatic means which willalso be described. The pneumatic means comprises apparatus formultiplying the effect of compressor discharge pressure variations andtransmitting amplified pressure variations to the diaphragm I2I. It willbe noted that the receiver pressure in the receiver 9 (Figs. 1 and 11)is transmitted through a conduit I25 to a mechanism I23 to act within apressure-responsive device, herein a Bourdon tube I21. Receiver pressureis also transmitted to this mechanism through a conduit I28, a pressurereducing valve I29 and a further conduit I30, and this low pressure airis delivered past a throttling device I3I and through a conduit I32 to aspace I33 between the diaphragms I20 and I2I. Means for effectingsubstantial variations in the pressure within the space I33 in responseto comparatively small variations of the pressure within the receiverincludes a vent valve mechanism I35 (see Fig. 8) which is connectedthrough a conduit I36 to the conduit I30 so that the pressure at thedischarge side of the throttling device I3I may be bled down rapidlywhen the vent device I35 is opened. The vent device includes herein adouble-beat vent valve apparatus I31 having a stem I33 which rests upona pivoted lever I39. The fulcrum I40 of this lever is adjustable bothlongitudinally of the lever and up and down by well-known means, andthis structure is not per se my invention, but a well-known device oi.commerce. It will be understood by reference to Figs. 8 and 11 that whenthe pressure within the receiver 9 rises, the Bourdon tube I21 will tendto straighten out and to raise the left-hand end of the lever I33. Thiswill allow seating of the double-beat valve mechanism I31, and since thepressure will not be permitted to escape from the space I33, it willrise to that value which is permitted by the pressure reducing valveI29. Accordingly, the diaphragm I2I will be forced to the left and willdisplace liquid beneath the diaphragm 23 and move thesteam-flow-regulating valve I8 in a closing direction. This will causethe steam engine I0 to slow down, and accordingly, the rate of airdischarged by the compressor will be reduced, and if the air consumptionrate is not also reduced the pressure in the receiver 9 will graduallybe lowered until such time as the reduction in pressure within theBourdon tube I21 will cause the latter to move from a positionpermitting the valve I31 to be closed to a position opening that valve.Then, since the bleeding capacity of the double-beat valve device I31exceeds the air supply rate past the throttling device I3I, the pressurein the space I33 will be rapidly reduced, and the spring 33 will beenabled then to force the steam-flowregulating valve I3 in an openingdirection.

It may now be noted that if the compressor.

runs at too high a speed, this increased speed will be effective throughaction of pressure applied through .the thrust ball 80 upon thediaphragm I20 and the pressure transmitted by the diaphragm I20 againstthe diaphragm I2I also to effect a raising of the diaphragm 23 in acontrolling valve closing direction. It will still further be noted thatif the compressor should overspeed for any reason, the automatic safetystop through releasing the compression of the spring 93 would allow thespeed-responsive wabble plate to move in such a manner as will cause thethrust ball 80 to exert the necessary pressure on the diaphragm I20 toeffect stopping of the steam engine I0. Ifthe drive for the governorbreaks, the cam 85 will also act to reduce or interrupt the supply offiuid past the steam-flow regulating valve I8. Thus it may be noted thatthe compressor driving engine has its speed automatically controlled bypressures transmitted through a single diaphragm both in response tocompressor discharge pressure variations and to variations in enginespeed, these latter variations being transmitted to the first diaphragmthrough a second one. It will further be noted that the engine is undersubstantial instantaneous manual control; is guarded against overspeed;is guarded against breakage in the governor drive, and is guardedagainst the springing of a leak in the hydraulic control system for thediaphragm 23.

In Figs. 12 and 13 there is disclosed a modified form ofspeed-responsive means whereby different settings of thespeed-responsive, weighted control means may be obtained to meet varyingoperating conditions. In this construction, which is similar to thatshown in Figs. 2 and 3, the tubular shaft, driven through the chain andsprocket connections 89, 9| and 92 from the compressor crank shaft 90,is designated by the reference character I50, and the sleevecorresponding to the sleeve 68 is designated I5I. Both the shaft andsleeve are of substantially greater length than those described above inregard to the other form of the invention. The tubular shaft I50 isjournaled in bearings supported within the casing of the mechanism, asin the form of the invention above described. The sleeve I5I 'haspivotally mounted thereon at I52 at opposit sides thereof, a pair ofarms I 53 connected at one end by a bolt I54 carrying a weight I55. Theother ends of the arms I53 have mounted thereon by bolts I56, weightsI51, I51 respectively. The tubular shaft I50 supports a sliding collarI58 which is pivotally connected to one end of a link I59. The oppositeend of the link I59 is pivotally connected at I60, as by a bolt I6I, toa pair of arms I62, I62. These arms are slidably guided in guideways I63formed on the inner adjacent sides of the weights I51 and are slotted atI64 to permit adjustment thereof in the weight guideways. The bolts I56also serve as securing means for holding the arms I62 in their adjustedposition in the weight guidways. The sliding collar I58 is connected bya transverse pin I65 extending through longitudinal slots I66 in thetubular shaft I50, to a cylindric slide member I61 movable within thebore I68 of the shaft. A rod I69 connects the slide member I61 withanother slide member I10 also movable within the shaft bore and whichhas fixed thereto a projecting rod element I" for actuating, through thethrust ball 80, the diaphragms I20, I2I of the liquid control system, inthe manner described above. The slide member I61 has fixed thereto aprojecting spindle-like element I12 corresponding to the element 84 andsimilarly engaging th cam surface of the cam 85 on the arm 86 whichcarries the drive-chain-engaging idler sprocket 68. A spring I13 actingon the sliding collar I58 urges the latter toward the left in Fig.

13. A spring I14, more powerful than the spring I13, engages at itsright-hand end in Fig. 13 the collar I58, while its left-hand end isengaged by an adjustable stop member I corresponding to the stop member94 in the form of the invention above described. The member I15 hasassociated therewith the elements 91, I00, IOI, I02 and I03 and isprovided with the same form of latch means I06, I01, as in the otherform of the invention. When the tubular shaft is driven through thechain and sprocket connections 89, 9| and 92, the weighted arms I53provide a speedresponsive means for controlling the position of theprojecting element I1I, thereby to control, through the liquid controlsystem, the position of the steam-fiow-regulating-valve II8. When thespeed for any reason becomes excessive, the latch means I06, I01 isoperated to release the stop member I15 from the shaft I50, permittingthis stop member to move toward the left in Fig. 13, thereby to reducethe pressure exerted by the spring I14; and as a result, the spring I13effects movement of the sliding collar I58 relative to the shaft,thereby to actuate the projecting element I1I into a position to effect,through the liquidcontrol system, closure of thesteam-fiow-regulating-valve I I8. By the provision of the adjustablearms I62, the setting of the angle of the weighted arms I53 of thecontrol means may be varied so that the range of control of thespeedresponsive means may be correspondingly varied, thereby to meetdifferent operating conditions, in an obvious manner. Otherwise, thisform of the invention is the same as that above described.

While there are in this application specifically described one form anda modification which the invention may assume in practice, it will beunderstood that this form and modification of the same are shown forpurposes of illustration and that the invention may be further modifiedand embodied in various other forms without departing from its spirit orthe scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a controlling mechanism, in combination, a prime mover, means forsupplying motive medium thereto, a fluid control system including meansresponsive to the pressure of the fiuid in said system for controllingsaid supply means, and means responsive to the speed of said prime moverfor automatically regulating the pressure in said fluid control system.

2. In a controlling mechanism, in combination, a prime mover, a pumpdriven thereby, means for supplying motive medium to said prime mover, afiuid control system including means responsive to the pressure of thefiuid in said system for controlling said supply means, means responsiveto the speed of said prime mover for automatically regulating thepressure in said fiuid control system, and means automaticallyresponsive to the pressure of the pump discharge for regulating thepressure in said fiuid control system.

3. In a controlling mechanism, in combination, a prime mover, means forsupplying motive medium thereto, a pump driven by said prime mover, afluid control system including means responsive to the pressure of thefluid in said system for controlling said supply means, and meansresponsive to the pump discharge pressure for automatically regulatingthe pressure in said fiuid control system.

4. In a controlling mechanism, in combination,

a prime mover, a pump driven thereby, means for supplying motive mediumto said prime mover,

means responsive to the speed of said prime.

mover for automatically controlling said supply means, and associatedmeans automatically operative in the event of failure of a part of themechanism for automatically controlling said supply means.

5. In a controlling mechanism, in combination, a prime mover, means forsupplying a motive medium thereto, means responsive to the speed of saidprime mover for automatically controlling said supply means, meansdriven by said prime mover for driving said speed responsive means, andmeans automatically operative in the event of failure of a part of saiddriving means for automatically cutting of! the supply of motive mediumto said prime mover.

6. In a controlling mechanism, in combination, a prime mover, a pumpdriven thereby, means for supplying a motive medium to said prime mover,means responsive to the speed of said prime mover for controlling saidsupply means, means responsive to the pump discharge pressure forcontrolling said supply means, said two last mentioned means including acommon supply-means-control element through which supply control iseifected, and means operative in the event of failure of saidsupply-means-control element for automatically cutting ofi the supply ofmotive medium to said prime mover.

7. In a controlling mechanism, in combination, a prime mover, a pumpdriven thereby, means for supplying motive medium to said prime mover,hydraulic control means responsive to the speed of said prime mover forcontrolling said supply means, and hydraulic con trol means responsiveto the pump discharge pressure for controlling said supply means, saidhydraulic control means including a common hydraulic fluid system.

8. In a controlling mechanism, in combination, a prime mover, a pumpdriven thereby, means for supplying motive medium to said prime mover,hydraulic control means responsive to the speed of said prime mover forcontrolling said supply means, and hydraulic control means responsive tothe pump discharge pressure for controlling said supply means, saidhydraulic control means including a common hydraulic fluid system andsaid fluid system including a fluid chamber adapted to contain anactuating fluid and having a movable wall actuated by said speedresponsive means and said pump-discharge-pressure responsive means.

9. In a controlling mechanism, in combination, an air compressor, asteam engine for driving said air compressor, means for supplying steamto said steam engine, a valve for controlling the flow of steam throughsaid supply means, a fluid control system for controlling said valve,means responsive to the speed of said steam engine for controlling thepressure in said fluid control system, and means responsive to thecompressor discharge pressure for controlling the pressure in said fluidcontrol system.

10. In a controlling mechanism, in combination, an air compressor, asteam engine for driving said compressor, means for supplying steam tosaid engine, a valve for controlling the flow of steam through saidsupply means, a fluid control system for said valve including adiaphragm containing chamber, means responsive to the speed of saidsteam engine for actuating said diaphragm to control the pressure Saidfluid control system, and means responsive to the compressor dischargepressure for actuating said dias phragm to control the pressure in saidfluid control system.

11. In a controlling mechanism, in combination, an air compressor, asteam engine for driving said air compressor, means for supplying steamto said steam engine, a valve for controlling the flow of steam throughsaid supply means, a fluid control system for controlling said valve,means responsive to the speed of said steam engine for controlling thepressure in said fluid control system, means responsive to thecompressor discharge pressure for controlling the pressure in said fluidcontrol system, and means automatically operative in the event offailure of a part of said speed responsive means for automaticallycontrolling the pressure in said fluid control system.

12. In a controlling mechanism, in combination, an air compressor, asteam engine for driving said compressor, means for supplying steam tosaid engine, a valve for controlling the flow of steam through saidsupply means, a fluid control system for said valve including adiaphragm containing chamber, means responsive to the speed of saidsteam engine for actuating said diaphragm to control the pressure insaid fluid control system, means responsive to the compressor dischargepressure for actuating said diaphragm to control the pressure in saidfluid control system, and means automatically operative in the event offailure of a part of said speed responsive means for actuating saiddiaphragm to control the pressure in said fluid control system.

13. In a controlling mechanism, in combination, a control element, speedresponsive means for controlling said control element, and meansautomatically operative in the event of an excessive speed forautomatically varying the normal controlling action of said speedresponsive means.

14. In a controlling mechanism, in combination, a control element, speedresponsive means for controlling said control element, and meansautomatically operative in the event of an excessive speed forautomatically varying the normal controlling action of said speedresponsive means, said automatically operative means including aseparate speed responsive controlling means.

15. In a controlling mechanism, in combination, a control element, speedresponsive means for controlling said control element, and meansautomatically operative in the event of an excessive speed forautomatically varying the normal controlling action of said speedresponsive means, said automatically operative means including a latchmeans for rendering a part of said speed responsive means less effectiveand a separate speed responsive means for controlling said latch means.

16. In combination, in a speed-responsive controlling device, a movablecontrolling element, speed-responsive means for moving said element in adirection to reduce the speed of the device controlled thereby, yieldingmeans tending to oppose the movement of said speed-responsive means, anadjustable abutment against which said yielding means reacts, and speedresponsive means for automatically releasing said abutment to reduce theopposition of said yielding means to said speed responsive meansautomatically upon excess speed.

17. In a controlling mechanism, in combination, an element movable inone direction to reduce the speed of a device controlled by saidcontrolling mechanism, speed-responsive means operative on increasingspeeds to move said element in said direction, driving means for saidspeed-responsive means, and means for moving said element in saidspeed-reducing direction automatically upon release normally heldinoperative by said driving means.

18. In combination, a prime mover, a pump driven thereby, a device forvarying the operating medium supply to said prime mover, an actuatingmeans for said device including an enclosed hydraulic system havingelements respectively movable to control the position of said device andmovable to move the liquid in said hydraulic system to move said firstmentioned element, means controlled by the speed of said prime mover formoving said second-mentioned element, and means controlled by thedischarge pressure of said pump for also moving said second mentionedelement.

19. In combination, in a controlling mechanism for a prime mover, adevice for regulating the operating medium supply to said prime mover, ahydraulic system for adjusting the position of said device, a deviceoperative when released to move said first mentioned deviceautomatically completely to interrupt the supply of operating medium tosaid prime mover, and means for automatically releasing said lastmentioned device upon loss of liquid from said hydraulic system.

20. In combination, in a pumping system, a pump, a prime mover drivingsaid pump, operating medium supply means for said prime mover, andautomatic controlling means for said operating medium supply meansincluding cumulatively acting mechanism for regulating the operatingmedium supply automatically in accordance with the speed of said primemover and the pump discharge pressure.

21. In a controlling mechanism,.in combination, an element to becontrolled, 2. controlled hydraulic operating system for said elementincluding a chamber having a movable wall changes in whose positioneffect control, means cooperating with said wall to form a secondchamber and including another movable wall spaced from said first wall,means for transmitting movement to said second wall and through thelatter to said first mentioned wall to effect control, and means foralternatively supplying fluid to and venting fluid from the spacebetween said walls for exercising a diflerent control.

22. In a controlling mechanism, in combination, a prime mover, means forsupplying a motive medium thereto, a fluid control system includingmeans responsive to the pressure of the fluid in said system forcontrolling said supply means, means responsive to the speed of saidprime mover for automatically regulating the pressure in said fluidcontrol system, and associated means automatically operative in theevent of failure of a part of the controlling mechanism for effecting anincrease in pressure in said fluid control system.

23. In a controlling mechanism, in combination, a prime mover, a pumpdriven thereby, means for supplying motive fluid to said prime mover, avalve for controlling the flow of motive fluid through said supplymeans, means for controlling said valve including a movable member,means responsive to the speed of said prime mover for actuating saidmovable member, means responsive to the pump discharge pressure foractuating said movable member, and means automatically operative in theevent of failure of a part of said speed responsive means for actuatingsaid movable member to effect closure of said valve.

24. In a controlling mechanism,- in combination, a prime mover, a pumpdriven thereby, means for supplying motive fluid to said prime mover, avalve for controlling the flow of motive fluid through said supplymeans, a controlled hydraulic operating system for said valve includinga chamber having a movable wall, changes in whose position effectcontrol, means cooperating with said wall to form a second chamber andincluding another movable wall spaced from said first wall, meansresponsive to the speed of said prime mover for transmitting movement tosaid second wall and through the latter to said first mentioned wall toeffect control, and means for alternatively supplying pump dischargepressure to and venting pressure from the space between said walls forexercising a different control.

25. In a controlling mechanism, in combination, an air compressor, asteam engine for driving said air compressor, means for supplying steamto said steam engine, a valve for controlling the flow of steam throughsaid supply means, a fluid control system including means responsive tothe pressure of the fluid in said system for controlling said valve,means responsive to the speed of said steam engine for controlling thepressure in said fluid control system, and means automatically operativein the event of an excessive speed of said steam engine for controllingthe pressure in said fluid control system.

26. In a controlling mechanism, in combination, an air compressor, asteam engine for driv-' ing said compressor, means for supplying steamto said engine, a valve for controlling the flow of steam through saidsupply means, a fluid control system for said valve including adiaphragm containing chamber, means responsive to the speed of saidsteam engine for actuating said diaphragm to control the pressure insaid fluid control system, means responsive to the compressor dischargepressure for actuating said diaphragm to control the pressure in saidfluid control system, and means automatically operative in the event ofan excessive speed of said steam engine for rendering said speedresponsive means more effective to control the pressure in said fluidcontrol system.

27. In a controlling mechanism, in combination, a prime mover, a pumpdriven thereby, means for supplying motive fluid to said prime mover, avalve for controlling the flow of motive fluid through said supplymeans, means for controlling said valve including a movable member,means responsive to the speed of said prime mover for actuating saidmovable member, means responsive to the pump discharge pressure foractuating said movable member, and means automatically operative in theevent of an excessive speed of said rime mover for effecting actuationof said movable member in a valve closing direction.

ALEXANDER D. FERGUSON.

